Yeah this happened to me too. Seemed to always happen around the end of the day for me, but that could just be coincidence.
I think it may be caused by a bug in the code they added this week which makes the AI rearrange your roster for you because it detects that you're doing something funky (such as pitching position players, incomplete starting rotation, etc)
http://www.ootpdevelopments.com/boar...d.php?t=296563